DENVER — A suburban Denver teenager facing prison over accusations she sought to join violent jihad against Americans has indicated she may plead guilty.

Shannon Conley, 19, was arrested in April at Denver International Airport by federal investigators who said they repeatedly warned that her actions were illegal. The Arvada, Colo., teen was arrested on the jetway as she tried to board a plane on a one-way trip to the Middle East, court documents show.

Conley's attorney has now filed a "notice of disposition," which generally indicates she's preparing to change her not guilty plea, the U.S. Attorney's office in Denver said Monday.

Court documents unsealed in the case in July paint a picture of a self-isolated woman who fell in love with a Tunisian man online, converted to Islam after reading about it on the Internet and became obsessed with religious war.

FBI agents said Conley, a certified nurse's aid, sought and practiced military tactics so she could fight on behalf of the Islamic State, which recently seized portions of Iraq. She also showed FBI agents a book detailing guerrilla warfare tactics and said she could carry out jihad in America.

"Conley believed she, as a Muslim, needed to marry young and be confrontational in her support of Islam," a U.S. anti-terrorism agent wrote in an arrest affidavit. "Special Agent Khomssi admonished Conley twice in the conversation that travel with intent to wage jihad may be illegal and result in her arrest."

A hearing for the federal court to accept Conley's potential plea change has not yet been scheduled, prosecutors said.

Conley remains in federal custody and is charged with attempting to provide material support or resources to a terrorist organization. If convicted of that charge she faces up to 15 years in prison, a fine of up to $250,000, or both.